hyc_symas

6 ms·

1.
by hyc_symas 2mo ago
> A power outage interrupted Garage mid-write on the LMDB metadata database. LMDB uses mmap’d I/O and, by default, operates with MDB_NOMETASYNC and MDB_NOSYNC (Garage sets metadata_fsync = false by default) No, Garage disables L
2.
by hyc_symas 3mo ago
The txnID was added to the page header to enable support for incremental backup. As a consequence, it's sufficient to compare a page's txnID to the current txnID to know if it's dirty or not, and spilled pages don't need
3.
by hyc_symas 3mo ago
write/fsync can be faster in a large dataset because writes let the filesystem know an explicit list of dirty pages, so fsync only needs to deal with them. mmap/msync gives no hints about which pages are dirty (unless the app trac
4.
by hyc_symas 3mo ago
By the way, you're wrong on both points - the cache of page mallocs is not infinite, and it does spill dirty pages to disk when necessary. And the latter is what bounds the number of malloc'd pages.
5.
by hyc_symas 3mo ago
You're dreaming. None of your explicit memory control operations mean anything in practice, because today everything runs in VMs with no actual control of the underlying hardware. Probably co-resident with an unknown number of other te
6.
by hyc_symas 3mo ago
In the time it takes for your query optimizer to dissect a query and "look ahead" LMDB would have already answered a million queries. You think your magical "future oracle" is zero cost? How many KLOCs is it? LMDB's
7.
by hyc_symas 3mo ago
Indeed, there's no need to use the doc website. There's nothing there that isn't embedded in the LMDB source code. All of the docs are generated from doxygen comments in the source.
8.
by hyc_symas 3mo ago
If you're downloading binaries from a plaintext documentation site, I think that's on you.
9.
by hyc_symas 3mo ago
Nonsense. The best you will ever do, even with full application knowledge and complete control of the machine, is an LRU cache replacement algorithm. But when you do it yourself you have to juggle the fine details of which indices to priori
10.
by hyc_symas 3mo ago
Obligatory "that paper is garbage" https://www.symas.com/post/are-you-sure-you-want-to-use-mmap...
11.
by hyc_symas 3mo ago
Irrelevant, since LMDB doesn't dirty the pages in the mmap. The mmap is read-only.
12.
by hyc_symas 3mo ago
LMDB 1.0 no longer uses a P_DIRTY flag, it no longer has to explicitly mark pages as clean.
13.
by hyc_symas 5mo ago
> The price is intended to decrease. No. Monero's tail emission rate was specifically chosen to be less than the rate of global gold production. Do you claim the price of gold is intended to decrease? A continuous emission like Mone
14.
by hyc_symas 5mo ago
I don't know what the current versions do, it's been a while since I touched that code. I have no reason to lie, I'm not selling anything. Bitmain is selling mining hardware, take a look at their claims. They've had 7 ye
15.
by hyc_symas 5mo ago
FPGAs have no particular advantage. You could dedicate a chunk of their resources to implement a softcore CPU but it'd be several times slower than a real CPU. The random programs change too quickly to just implement them directly on a
16.
by hyc_symas 5mo ago
> Loved your 2019 talk on "is XMR still ASIC-proof" – is it still, in 2026, in your opinion? Yep. Nothing about computing architecture has changed.
17.
by hyc_symas 5mo ago
>> just killing the process will never corrupt the blockchain DB > I would love to show you how easy this is to reproduce, even on fresh installs of Ubuntu and/or MacOS on otherwise-stable hardware (never tried Windows... easi
18.
by hyc_symas 5mo ago
> If you don't sync then you're not (cannot be) a fullnode / network verifyer / ringsigner. I was talking about database sync, not blockchain sync. You don't need to use safe sync mode if you don't have to w
19.
by hyc_symas 5mo ago
Light mode is used mostly by the monerod, validating incoming blocks. But on a machine with sufficient free RAM, monerod can also be set to use Fast mode instead. The post described both modes. The only difference is that Fast mode processe
20.
by hyc_symas 5mo ago
The limit we set at the beginning was "no one can design a custom device for RandomX with more than a 2:1 efficiency advantage over general purpose CPUs". That is and will forever remain true. In reality, no one has been able to b
21.
by hyc_symas 5mo ago
Since the programs are randomly generated, there's no guarantee that any particular program always uses some number of any particular instruction. There's only a probability, X/256 instructions will be somesuch operation.
22.
by hyc_symas 5mo ago
Monero is disinflationary , not inflationary. The rate of new coin emission is only enough to maintain equilibrium with the rate of coins being lost (due to people losing wallet keys, etc.). So your comment about being forced to keep earni
23.
by hyc_symas 5mo ago
You must be on drugs. There is no separate specialized verification function. It's the same algorithm for verification as for mining.
24.
by hyc_symas 5mo ago
PoW is useful in far more situations than PoS. A derivative of RandomX is now used to protect TOR too (Equi-X). https://github.com/tevador/equix/blob/master/devlog.md
25.
by hyc_symas 5mo ago
> Once you kill the process, your local blockchain is [most likely] unusable. Totally false. LMDB is perfectly crash-proof in that scenario and killing the process never damages the DB. The only thing that's not guaranteed is turnin
26.
by hyc_symas 5mo ago
No, Bitcoin is absolutely a waste by every measure. It was a prototype that never should have continued after all of its flaws became apparent.
27.
by hyc_symas 5mo ago
The design has been working perfectly from 2018 till today. https://old.reddit.com/r/Monero/comments/1h6e4nk/randomx_5_y... Most miners use AMD Ryzens. Couldn't tell you the actual breakdown of CPU
28.
by hyc_symas 5mo ago
Sorry, copy/paste error. Fixed now.
29.
by hyc_symas 5mo ago
ProgPow was ridiculously simple and would never have accomplished its goal. I covered it briefly in my Monerokon talk as well.
30.
by hyc_symas 5mo ago
Just use a Linux laptop with a working battery so you never have to worry about power outages or other system crashes. In that case, you don't need safe sync mode, and you don't have to kill your SSD.

More ›